The invention relates to a method of texture synthesis based on digital video signals and to a method of transmitting and/or storing texture signals providing, at the receiver end, a texture synthesis phase which comprises the steps of said synthesis method. The invention also relates to a synthesis device and to devices or systems of transmitting and/or storing texture signals for carrying out these methods.
The document "A new method for texture field synthesis: some applications to the study of human vision" by A. Gagalowicz, published in the magazine "IEEE Transactions on Pattern Analysis and Machine Intelligence", vol. PAMI-3, no. 5, Sep. 1981, pp. 520-533 describes a texture analysis method particularly taking statistical data which may be associated with texturized zones of a picture into account as analysis parameters. The textures found, for example in television pictures, which would theoretically be fbrmed by the periodical repetition of one or several patterns, are actually not rigorous arrangements of such basic elements and the models which describe these textures rightly support this uncertain notion. Starting from these general statistical considerations, the document specifically focuses on the study, based on psychovisual considerations, of the extent to which parameters such as the statistical moments of the second order may contribute to a local discrimination of textures distinguished by the human eye.
If the synthesis of a texture in conformity with an original is to be realised, such second-order statistics can be used as relevant parameters for the visual discrimination of two textures (in this case, the original texture and the synthesized texture). Nevertheless, if the second-order statistics of a white noise picture are converged with those of the original texture, the global structure which may exist in certain regular textures (for example of the brick wall type) may be lost. The resultant picture seems to be forrned as a ragged texture, like a kind of patchwork, with the individual patches being well formed but appearing to be incoherent when assembled, without any bond between them.